Steel is the number one recycled metal on earth. Almost every product made in the world contains some steel.
There are many different grades and alloys all are worth different amounts. Cast iron, stainless steel, sheet metal, construction steel, ect.
Stainless steel: is worth about 5 times as much as regular steel,
Cast iron: is another one that is usually at a premium because the material is at a more virgin state, also item like cast iron engine blocks and machine tools are made from very pure alloys.
Construction steel: The most common seen would be I - Beams, Steel plate, and pipe and tubing. This material is worth more bare and unpainted. But most salvage companies will give you a good rate on it either way.
Sheet Metal: This is by far the most common. Our cars, office furniture, shelves, soup cans, ect are all made from sheet steel. The rate for sheet steel is one of the lowest because if it is painted or plated the recovery rate of pure alloy is less than with the other forms mentioned.
CLIPPINGS: These are the sheet metal slugs from industrial stamping operations. These are generaly worth more money then clean steel solids, because they are already in size the mills can use.
Metal turnings: These are the shavings left from machining operations. This material is worth slightly less that construction steel because of contamination from cutting oils, and foreign materials.
Copper and copper alloys such as Brass and Bronze, have one of the highest cost per pound rates of non precious metals.
Good copper and copper alloy sources include: copper pipe, plumbing fixtures, bronze bearings, copper wire, transformers, electric motors, copper trim, buss bars, light balasts, cooking pots, door knobs, circuit boards, ect.
The great thing about copper and copper alloys is you don't need very much to make allot of money. Currently at the writing of this article copper is at $3.15 per pound.